The present invention relates to an insulating curtain, for continuous slab-heating furnaces and the like, for reducing loss of heat at product entry and exit openings, while allowing for substantially unrestricted entry and exit of product through those openings.
In the rolling of steel, it is often necessary to heat slabs, billets, bars and the like prior to hot rolling. Such heating, which is most often carried out in a continuous furnace, may be required to raise the metal to a temperature suitable for hot rolling, or the heating may be needed to bring the metal to an even temperature throughout. Substantial heat is required for operation of such furnaces, and such furnaces represent a substantial expense, and account for considerable heat loss in a mill. In order to conserve heat and to reduce operating expense, it is desirable to close the entrance and exit openings of the continuous furnace with an insulating curtain which will restrict loss of heat while still enabling a slab or the like to enter or exit the furnace.
It is an object of the present invention to provide an insulating curtain for closing off of an entry opening and an exit opening of a continuous reheating furnace for heating slabs, billets, bars, and like products.
It is a further object of the present invention to provide such insulating curtain with side-by-side sections to enable opening of solely a portion of the curtain which is encountered by the entering or exiting product of various widths.
It is a further object of the present invention to provide an insulating curtain, which is opened by movement of the product being processed along a horizontal conveying surface, and closed by the force of gravity.
It is still a further object of the present invention to provide an insulating curtain which provides horizontally hinged movement at a plurality of heights above the conveying surface, so as to accommodate products of varying thicknesses.
It is yet a further object of the present invention to provide an extremely durable insulating curtain to resist the harsh conditions present at openings of a continuous furnace.
The present invention is an insulating curtain assembly for a continuous heating furnace. The furnace has a product entry opening and a product exit opening at longitudinal ends of the furnace. Each opening extends horizontally between furnace side walls and extends vertically from a product conveying surface to a furnace end wall. The curtain assembly has a woven metal-wire fabric having a plurality of elongated segments arranged side-by-side and hingedly connected to each other along hinging axes, for hanging vertically in a furnace opening with the hinging axes oriented parallel to the conveyor surface. The curtain assembly also has a thermal insulating fabric arranged as a backing to at least a portion of the woven metal-wire fabric, for providing an insulating heat barrier at the furnace opening. When hanging vertically in the furnace opening, a face of the woven metal-wire fabric is directed so as to be encountered by product moving along the product conveying surface in order that the thermal insulating fabric is protected from encountering the product.